1. Field of the Invention
This invention relates to locking devices, and more specifically to electronic sensing of physical key patterns, electronic latching, and general configurations for electronic locks.
2. Description of Prior Art
Access control devices, that involve physical tokens carried by the persons who may wish to gain access, fall into two categories. One uses tokens requiring electronic means of reading, such as magnetic stripe cards, smart cards, keys containing chips, or other elements encoding and/or communicating information electromagnetically. The other, which is the subject of this invention, uses tokens originally intended to be read by mechanical means. Most people in the developed world carry with them many such access tokens--in the form of metal keys.
There are a variety of widely appreciated deficiencies or problems with mechanical key lock systems:
Many people would prefer to carry far fewer keys than they must today. PA1 Individual keys cannot usually be revoked, requiring the change of locks and distribution of an new keys, even if only one key may be in the wrong hands. PA1 Most locks can be picked readily--using tools and techniques that are apparently available beyond the professional locksmith community. PA1 Temporary users may not return keys issued them, such as with keys for hotels and rental cars. PA1 Keys must often be left "under the doormat" or entry obtained in some other way, since keys must be physically present at the time of entry. PA1 Keys must be physically returned by previous users and provided to new users. PA1 There is record neither of who has gained access nor when.
The present invention has the solution to the above problems among its objects. Other objects, features, and advantages of the present invention will be appreciated when the present description and appended claims are read in conjunction with the drawing figurers.